This invention relates to hair colorants containing a combination of hair care ingredients and to a coloring process using this combination.
Nowadays, human hair is treated in many different ways with hair-care preparations. Such treatments include, for example, the cleaning of hair with shampoos, the care and regeneration of hair with rinses and treatments and the bleaching, coloring and shaping of hair with coloring and tinting formulations, wave formulations and styling preparations. Among these, formulations for modifying or shading the color of the hair occupy a prominent position.
So-called oxidation colorants are used for permanent, intensive colors with corresponding fastness properties. Oxidation colorants normally contain oxidation dye precursors, so-called primary intermediates and secondary intermediates. The primary intermediates form the actual dyes with one another or by coupling with one or more secondary intermediates under the influence of oxidizing agents or atmospheric oxygen. Combinations of oxidation dyes and substantive dyes are often also used to obtain special shades. Oxidation colorants are distinguished by excellent long-lasting coloring results.
Colorants or tints containing substantive dyes as their coloring component are normally used for temporary colors. Substantive dyes are based on dye molecules which are directly absorbed onto the hair and do not require an oxidative process for developing the color. Dyes such as these include, for example, henna which has been used since ancient times for coloring the body and hair. Corresponding colors are generally sensitive to shampooing so that an often unwanted change of shade or even a visible “decoloration” can occur.
A disadvantage of temporary colors of the type in question is that they are added onto the natural hair color and hence only allow shades that are darker than the starting color. Because of this, colorants based on substantive dyes are often used in combination with preparations of oxidizing agents in order to lighten the starting color of the fibers besides actually coloring them.
Accordingly, both processes necessitate the use of strong oxidizing agents, such as hydrogen peroxide solutions for example. This can damage the hair to be colored which then has to be treated with corresponding hair care products to counteract the damage.
It has therefore long been standard practice to subject the hair to a special aftertreatment. In this special aftertreatment, the hair is treated with special active substances, for example quaternary ammonium salts or special polymers, normally formulated as a rinse. Depending on the formulation, this treatment improves the combability, hold and volume of the hair and reduces the number of split ends.
In addition, so-called combination preparations have very recently been developed to reduce the effort involved in the usual multistep processes, particularly where they are directly applied by the user.
Besides the usual components, for example for coloring the hair, these preparations additionally contain active substances which, previously, had been reserved for the aftertreatment preparations. Accordingly, the user has one less step to carry out. At the same time, packaging costs are reduced because one product less is used.
The active substances used in such combination preparations have to meet stringent requirements, particularly in regard to their stability, because the coloring creams normally have a high pH and the oxidizing agent preparations a low pH. In addition, incompatibilities between the various active substances and hence poor stability in storage have to be avoided.
Patent applications DE-A-199 14 927, DE-A-199 14 926 and DE-A-44 08 506 disclose such combinations of active substances for use in oxidative colorants. Nevertheless, corresponding preparations are still unsatisfactory in regard to their hair care properties, particularly on hair that does not readily lend itself to care, such as Japanese hair for example.
Accordingly, there is a still a need for active substances or combinations of active substances which would couple good hair care properties with ready biodegradability and which would not have any tendency towards unwanted accumulation on the hair.